The literal translation of 賈雨村言 is "賈雨村 said." At the same time, 賈雨村言 (Jiǎ yǔ cūn yán) and 假語村言 (false comments, villagers' words) have the same pronunciation... with the latter what the author really inferred.

Following is the ending paragraphs of the book in Chinese. Unfortunately, most of the English translations I found online did not go all the way to the ending chapter (Look forward to the day when someone completed the translation of all 120 chapters):

Kong Kong Taoist found Cao Xueqin and showed him the book... that's when Cao Xueqin deciphered that 賈雨村言 means 假語村言.

說到辛酸處，荒唐愈可悲。由來同一夢，休笑世人痴！

The ending poem... the way I see it... all the juicy things in life is like a dream... (and possibly for everyone). Thus, cut the people in this world some slacks and quit laughing at the inescapable silliness (Gotta be human speaking to the supernatural power including the almighty universe?). Of course, a layman's interpretation, back to 賈雨村言 la!